1. Technical Field
The present invention relates generally to wireless communication systems; and more particularly to a wireless communication system that may be accessed via a service control point by a customer application to determine the approximate location of a mobile unit operating within the wireless communication system.
2. Related Art
Cellular wireless communication systems are generally known in the art to facilitate wireless communications within respective service coverage areas. Such wireless communication systems include a "network infrastructure" that facilitates the wireless communications with mobile units operating within a service coverage area. The network infrastructure typically includes a plurality of base stations dispersed throughout the service coverage area, each of which supports wireless communications within a respective cell (or set of sectors). The base stations couple to base station controllers (BSCs), with each BSC serving a plurality of base stations. Each BSC couples to a mobile switching center (MSC) which also couples to the PSTN, the Internet and/or to other MSCs.
A wireless mobile unit operating within the service coverage area communicates with one or more of the base stations. The base stations route the communications to the MSC via a serving BSC. The MSC routes the communications to another subscribing wireless unit via a BSC/base station path (which may be the same BSC/base station path when the communications are with another subscribing unit serviced by the same base station) or via the PSTN/Internet/other network to terminating destination.
Various operating standards have been developed to standardize wireless communications. The wireless communication operating standards include, for example, the Advanced Mobile Phone Service (AMPS) standards, the Global Standards for Mobile Communications (GSMC), the Code Division Multiple Access (CDMA) standards and the Time Division Multiple Access (TDMA) standards. A standard that is employed in North America for interconnectivity of MSCs is the IS-41 standard. These operating standards set forth the technical requirements that facilitate compatible operation between equipment of differing vendors.
Mobile units are used for many differing applications. In many applications, they simply serve as telephones for their users. However, in other applications, they take the place of two-way radios. A particular example of such usage is when mobile units are provided to delivery or service personnel. The mobile units are used primarily for communication between a central office and the worker when the worker is dispatched. In such applications, the central office is frequently interested in the present location of the worker for scheduling purposes and progress updates. To determine a present location of the worker, the central office must call the worker via the mobile unit and request his or her present location. Such technique not only delays the worker but requires a central office person to complete the communication, retrieve the location information and update the worker's status.
Other applications also require location information. For example, when a mobile unit is employed to create a data link between a user and a remote computerized application, the location of the mobile unit is typically required by the remote computerized application, such as automobile navigation services. A technique used to provide the location information is to incorporate a Global Positioning System (GPS) receiver in the automobile, to couple the GPS receiver to a local computer system to record the GPS location of the automobile and to relay the GPS location to the remote computerized application via the mobile unit. Such an application, while appropriate for navigation services since exact coordinates are typically required, is expensive, requires substantial overhead and consumes significant wireless bandwidth.
Thus, there is a need in the art for a system that allows a central location to determine the location of a mobile unit without dedicated overhead or substantial wireless bandwidth consumption.